Understanding the Expanding Universe

What happens to the light from a star as it moves away from us at high speed?

• It becomes more blue.

• It remains unchanged.

• It disappears completely.

• It becomes more red.

What was Edwin Hubble's major discovery about the universe?

• The universe is shrinking.

• The universe is expanding.

• The universe is static.

• The universe is contracting.

How is Hubble's constant used in astronomy?

• To find the mass of planets.

• To determine the age of the universe.

• To calculate the distance to galaxies.

• To measure the brightness of stars.

What is the approximate value of Hubble's constant?

• 50 kilometers per second per megaparsec

• 70 kilometers per second per megaparsec

• 90 kilometers per second per megaparsec

• 110 kilometers per second per megaparsec

What is the significance of the linear relationship in Hubble's graph?

• It indicates a constant speed of light.

• It shows that the universe is contracting.

• It proves the existence of black holes.

• It suggests a proportional relationship between distance and velocity.

What does a redshift value of 3 indicate about the universe's size when the light was emitted?

• The universe was half its current size.

• The universe was a quarter of its current size.

• The universe was twice its current size.

• The universe was the same size as now.

What does the cosmic scale factor represent?

• The current size of the universe.

• The size of the universe when light was emitted.

• The speed of light.

• The mass of the universe.

In the physical model of the universe, what do the rubber bands represent?

• Black holes

• Galaxies

• Space itself

• Stars

Why do galaxies appear to move faster the farther they are from us?

• Because they are moving through space faster.

• Because space itself is expanding.

• Because they are larger.

• Because they are closer to the edge of the universe.

What concept helps explain why galaxies can appear to move faster than the speed of light?

• Galactic drift

• Space expansion

• Cosmic inflation

• Time dilation